The invention relates to a protocol for the secure receipt and transmission of data between a pair of correspondents and in particular for the secure receipt of data by a client in a client-server environment.
With the advent of the Internet and the proliferation of Internet users along with the dramatic increase in data baud rates, there has been a move to distributed computing. For example, in the windows environment, a browser may be used to access a website and download a HTML page. Within the page might be included a program applet much like an image that is contained within the page. The applet""s code is transferred from the server to the client system and executed by the client""s computer. There are also instances where software or program applets are provided from a server to a client.
In the cases where the client does not trust the server a protocol has to be implemented whereby the client is able to authenticate the server. Or more generally where the client does not know the server since the server will serve any client, i.e. any requester is potentially valid as far as the client is concerned. Furthermore the applets received from the server include in some instances a log-on applet received from the server. Thus there exists a need for a log-on applet authentication protocol. The documents titled xe2x80x9cSecurity Defects in CCITT Recommendation X.509-The Directory Authentication Frameworkxe2x80x9d, xe2x80x9cElliptic Curves Over Fp Suitable For Cryptosystemsxe2x80x9d, xe2x80x9cSecure User Access Control For Public Networksxe2x80x9d, and U.S. Pat. No. 5,434,918 are referenced as background art.
This invention seeks to provide a solution to the problem of server verification by a client.
According to an aspect of this invention there is provided a method of authenticating pair of correspondents C,S in an information exchange session to permit exchange of information there between, characterized in that:
a) the first correspondent C transmitting to the second correspondent S a first unique information,
b) the second correspondent S verifying the identity of C and generating a second unique information;
c) transmitting to C the first and second unique information;
d) the C verifying the first unique information to thereby establish currency of the session;
e) the first correspondent C then generating a third unique information and transmitting the third unique information to the S along with an information request;
f) the second correspondent S transmitting to C the requested information along with said second and third unique information;
g) said c verifying said third unique information to thereby establish currency of the request and verifying the second unique information to thereby establish currency of the session;
h) said C repeating steps e) to g) for each additional information requested by C.
Also, this aspect of the invention provides for apparatus for carrying out the method. Such an apparatus can comprise any computational apparatus such as a suitably programmed computer.